Allow to invoke fields as if they were methods.

frog/tests/leg_only/src/Closure7Test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+var foo;
+bar() => foo(3, 99);
+gee(f) => foo(fun: f);
+
+get foo2() => foo;
+bar2() => foo2(3, 99);
+gee2(f) => foo2(fun: f);
+
+globalTest() {
+  foo = () => 499;
+  Expect.equals(499, foo());
+  foo = (x, y) => x + y;
+  Expect.equals(102, bar());
+  foo = ([fun = null]) => fun(41);
+  Expect.equals(42, gee((x) => x + 1));
+
+  foo = () => 499;
+  Expect.equals(499, foo2());
+  foo = (x, y) => x + y;
+  Expect.equals(102, bar2());
+  foo = ([fun = null]) => fun(41);
+  Expect.equals(42, gee2((x) => x + 1));
+}
+
+class A {
+  static var foo;
+  static bar() => foo(3, 99);
+  static gee(f) => foo(fun: f);
+
+  static get foo2() => foo;
+  static bar2() => foo2(3, 99);
+  static gee2(f) => foo2(fun: f);
+}
+
+staticTest() {
+  A.foo = () => 499;
+  Expect.equals(499, A.foo());
+  A.foo = (x, y) => x + y;
+  Expect.equals(102, A.bar());
+  A.foo = ([fun = null]) => fun(41);
+  Expect.equals(42, A.gee((x) => x + 1));
+
+  A.foo = () => 499;
+  Expect.equals(499, A.foo2());
+  A.foo = (x, y) => x + y;
+  Expect.equals(102, A.bar2());
+  A.foo = ([fun = null]) => fun(41);
+  Expect.equals(42, A.gee2((x) => x + 1));
+}
+
+main() {
+  globalTest();
+  staticTest();
+}